2nd Gen Non-Engine/Transmission Am I nuts? Getting the truck ready for a haul.

[MLee]

You need RPM for the brake to be effective. Lower RPM does not produce enough back pressure so more service brake is required. Make sure you have every thing sealed and tight in that area also. As you mentioned 45 MPH, if your locked up in the lower gears then making the RPM needed should be no problem.

Good you got it put together and your on your way. Just the way it is.

 

[mwilson]

I got food poisoning when we left Midland and suffered/puked/etc all the way to Phoenix that night. We're in town here for a few days visiting my sister's family.



My truck is over at Chuck's Speed Shop getting a Pacbrake turbo-mount installed. Apparently a 3 hour job took all day and they've got some issues with it not working properly. I guess it's all wired/plumbed in and it says it's working, but he's not getting much braking force at city street speeds (~45mph). Pacbrake's tech support was AWOL this afternoon so the truck is out of commission until Monday. Bummer.



Anyone know of any issues running a Pacbrake on a 12-valve with a trans-go shift kit?

Good God Cosmo, are you going to survive this trip????



But they say that the things that go wrong are what make an adventure out of an ordinary trip... .



Keep your chin up (when you get done heaving that is. . )



Mike.

 

[HHhuntitall]

OH, yeah, keep the chin up, it helps align the passageways.....



Yeah, keep the rpms up, anyway. You need that to keep the pump pressure up enough to keep the clutches from slipping. I used to slip the clutches if I wasn't paying attention and lugged it through town. The lower RPM didn't build enough line pressure to keep the clutch locked, and it would slip if I got into the throttle too much. I never had it happen with the Ebrake, but I could see it happening...

 

[Cosmo]

Yeah, I know all about keeping the RPMs up... which is one of my biggest gripes about the 08 - it would shift into 5th and 6th at about 1400 rpm, which dropped the revs to ~1200 rpm, and if you backed off at all it would stay locked up in overdrive at as low as 900 rpm. Makes no sense at all, the torque that thing made at even 900 rpm (especially with the fuel turned up) would have chewed up the trans.

Anyway, I digress. They (Chuck's) say they've installed 4 other pacbrakes last week without issue, but I think mine has been the only 12 valve. It seems like everything is working properly, but it's not giving much brake force. That's what I'm being told anyway.

 

[Cosmo]

So they got in touch with Martin at Pacbrake, apparently I'm a member of the 1%, and not the good 1%. The controller had an intermittent problem so it was bad out of the box. Thankfully Chuck's had an install planned for today on an 05 and you can use the newer controller on an older truck (but not the other way around), so they're shipping the other guy a new controller and they gave me his (he has a bunch of work being done and won't even notice the delay).

Anyway, it's on and in theory working. I haven't had it up over 50, but it does seem to be closing, however I'm not all that impressed with the braking force generated. Granted, I don't have anything really to compare it to other than the VGT turbo on my old 08. I really like how that performed. This just doesn't seem as powerful. I do, however, think it will probably help with the load on hills. Anyone with a turbo mount pacbrake on an auto truck with 3. 55 gears and oversized tires care to comment on the effectiveness of their exhaust brake?

 

[KRStone]

Yes. Works great, but you need to have OD locked out (rpms higher), and realize that it will NOT downshift and re-engage like the newer trucks. This truck doesn't have the computer to do that.



Be sure the valve is clean and working (the manual has a cleaning procedure, and yes, it does have to be cleaned every now and then).



KRS

 

[KB0OU]

I had a in-line pacbrake on a International truck I ran for a while. Not a lot of braking but it did help on the long grades out west (Wyoming etc. )

Make sure you use it a lot, that helps keep it working and yes sometimes they need cleaned and massaged (tlc).

 

[NIsaacs]

Does your truck have the 60# valve springs? If it does, does the installer know this? Maybe he installed the brake for standard springs, 35 psi back pressure, or it is adjusted wrong.



Two of my trucks have the 35 psi brake and the '01 has the 60 psi brake. The 60 works twice as good, they are all standard trannys tho.



Nick

 

[sstefanini]

I just bought an auto 12v w/ 3. 55s 2wd and a Pacbrake. Once it builds pressure @ higher rpms it helps slow things down a little, but at lower rpms it's barely noticeable.

 

[Cosmo]

Does your truck have the 60# valve springs? If it does, does the installer know this? Maybe he installed the brake for standard springs, 35 psi back pressure, or it is adjusted wrong.



Two of my trucks have the 35 psi brake and the '01 has the 60 psi brake. The 60 works twice as good, they are all standard trannys tho.



Nick

Yeah, I put all 12 60# springs in it prior to leaving FL. The installer knew it, as we discussed it over the phone and again when I got there.



How can I tell if it's the higher pressure kit?



I find it quite annoying that it'll engage in OD, but if I hit the OD Off button the truck downshifts but the TC won't lock up again unless I get on the gas for a second or two.



What I really want to do is yank the stupid auto out and put a manual in. Before owning this truck I had an 08 with the 68rfe and I figured how much worse could the 47re possibly be.



It's that much worse.

 

[JMcCoy]

I have heard of people installing a mystery switch that engages the tc. I have ATS TC controller that allow me to adjust exactly what speed the TC will lock up. It is excellent. On of the best mods I did was install the Potentiameter to bypass the throttle positioning sensor. The potentiameter allows me to adjust exactly what speed the transmission will shift into od. Best of all, it was very easy and cost around $15. I believe thoughs two mods will change the way you feel about the 47re.

 

[KB0OU]

When I am going down a long grade I just hit the transmission switch that locks out high (overdrive) and flip the mystery lockup switch and ride like that down the hill, it helps a lot. ymmv

 

[NIsaacs]

[QUOTE=Cosmo;

How can I tell if it's the higher pressure kit?





Maybe by the model # of the brake? Is it the PRXB (pressure regulated) or the "fixed orifice"? When you turn it on, stopped in park or neutral, will the RPM drop about 50/100 RPM? When you are going down hill, will the transmission force the RPM up with the brake on? Does it feel like a transmission issue or the brake? I know you are on the road so it is hard to work on, but a back pressure gauge will tell you what is wrong if it is brake related.



Nick

 

[Cosmo]

I'm not exactly on the road any more, we're couch surfing with relatives until we can move into our new place.

It feels more like a brake issue, as the TC is locking up it just doesn't feel like it slows the truck down all that much more than the engine drag alone.

Basically I leave it on all the time, when it's in warm-up mode I can hear a difference but I haven't noticed it drop the RPM at all.

 

[Cosmo]

Ok so as I posted in the 12-valve forum, I got it fixed - the test port on the brake housing is definitely not a viable EGT probe port. It bent my probe about 45 degrees and kept the brake from working properly. Lesson learned.

I also figured I had more power on the table, since I set the AFC housing and the fuel plate dead center (where they were from the factory, more or less), so I moved them both full forward.

The truck actually smokes now under load - but not nearly as much as my 08 did with the wick turned up all the way. General commuting it doesn't smoke at all, but the throttle response is much smoother and faster, and the truck is notably quicker. Now I just wish the TC locked up much earlier. The 2-disc converter I've got just feels loose - RPMs will zip up to about 2800.